Method of transmitting uplink signal from user equipment in a wireless communication system supporting unlicensed band and apparatus supporting the same

Abstract

Disclosed herein is a method of transmitting a UL signal from a user equipment (UE) in a wireless communication system supporting an unlicensed band and apparatuses for supporting the same. More specifically, the present invention provides an embodiment in which the UE performs autonomous uplink transmission and scheduled uplink transmission through the unlicensed band, a method of adjusting contention window size when the UE perform the autonomous uplink transmission through the unlicensed band, and an embodiment of performing the autonomous uplink transmission based on the method.

The invention claimed is: 
     
       1. A method performed by a user equipment (UE) operating in a wireless communication system, the method comprising:
 performing an autonomous uplink (AUL) transmission starting before time unit n using a channel access procedure (CAP) on a unlicensed band, wherein n is an integer; 
 receiving a UL grant for a scheduled uplink (SUL) transmission to begin at the time unit n on the unlicensed band; 
 based on a priority class value for channel access for the SUL transmission being larger than a priority class value for channel access for the AUL transmission, terminating the AUL transmission, while the AUL transmission is ongoing and before the AUL transmission ends, such that a time gap remains after the AUL transmission and before the time unit n at which the SUL transmission is scheduled to start; and 
 performing the SUL transmission starting from the time unit n on the unlicensed band. 
 
     
     
       2. The method of  claim 1 , wherein the time gap comprises one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols. 
     
     
       3. The method of  claim 1 , wherein terminating the AUL transmission such that the time gap remains before the time unit n comprises:
 terminating the AUL transmission such that one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols remain after a last OFDM symbol of the terminated AUL transmission and before an initial OFDM symbol of the SUL transmission. 
 
     
     
       4. The method of  claim 1 , wherein the time unit n is one of:
 a first time unit where a first time interval configured for the AUL transmission overlaps with a second time interval scheduled for the SUL transmission, or 
 a second time unit following a third time unit configured for the AUL transmission. 
 
     
     
       5. The method of  claim 1 , wherein the AUL transmission is activated based on a first downlink control information (DCI), and
 wherein the AUL transmission is released based on a second DCI. 
 
     
     
       6. The method of  claim 5 , wherein the first DCI is distinguished from the second DCI based on a value of a first field of the first DCI and a value of a first field of the second DCI, and
 wherein the first field of the first DCI and the first field of the second DCI are timing offset fields. 
 
     
     
       7. The method of  claim 6 , wherein a second field of the first DCI and a second field of the second DCI have an identical value, and
 wherein a second field of a third DCI for acknowledgement of the AUL transmission has a different value from the second field of the first DCI and the second field of the second DCI. 
 
     
     
       8. The method of  claim 7 , wherein the second field of the first DCI, the second field of the second DCI, and the second field of the third DCI are physical uplink shared channel (PUSCH) trigger A fields. 
     
     
       9. The method of  claim 7 , wherein the first DCI, the second DCI and the third DCI have an identical size. 
     
     
       10. The method of  claim 7 , wherein the first DCI, the second DCI and the third DCI are scrambled by a radio network temporary identifier (RNTI) different from a cell-RNTI (C-RNTI). 
     
     
       11. The method of  claim 1 , wherein based on the priority class value for channel access for the SUL transmission being larger than the priority class value for channel access for the AUL transmission:
 the SUL transmission starts from the time unit n after the time gap which corresponds to performing a CAP for the SUL transmission after terminating the AUL transmission. 
 
     
     
       12. The method of  claim 1 , wherein based on the priority class value for channel access for the SUL transmission being larger than the priority class value for channel access for the AUL transmission:
 the SUL transmission starts from the time unit n after the time gap which corresponds to performing a listen-before-talk (LBT) procedure for the SUL transmission after terminating the AUL transmission. 
 
     
     
       13. The method of  claim 1 , wherein based on the priority class value for channel access for the AUL transmission being equal to or larger than the priority class value for channel access for the SUL transmission:
 the SUL transmission starts from the time unit n without the time gap after the AUL transmission ends. 
 
     
     
       14. The method of  claim 1 , wherein the priority class value for channel access for the SUL transmission is determined based on the received UL grant. 
     
     
       15. The method of  claim 1 , wherein a sum of a duration of the AUL transmission and a duration of the SUL transmission does not exceed a maximum channel occupancy time (MCOT) for the AUL transmission. 
     
     
       16. A user equipment (UE) configured to operate in a wireless communication system, the UE comprising:
 a transceiver; 
 at least one processor; and 
 at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, perform operations comprising: 
 performing, through the transceiver, an autonomous uplink (AUL) transmission starting before time unit n using a channel access procedure (CAP) on a unlicensed band, wherein n is an integer; 
 receiving, through the transceiver, a UL grant for a scheduled uplink (SUL) transmission to begin at the time unit n on the unlicensed band; 
 based on a priority class value for channel access for the SUL transmission being larger than a priority class value for channel access for the AUL transmission, terminating the AUL transmission, while the AUL transmission is ongoing and before the AUL transmission ends, such that a time gap remains after the AUL transmission and before the time unit n at which the SUL transmission is scheduled to start; and 
 performing, through the transceiver, the SUL transmission starting from the time unit n on the unlicensed band. 
 
     
     
       17. An apparatus configured to control a user equipment (UE) to operate in a wireless communication system, the apparatus comprising:
 at least one processor; and 
 at least one memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, cause the UE to perform operations comprising: 
 performing an autonomous uplink (AUL) transmission starting before time unit n using a channel access procedure (CAP) on a unlicensed band, wherein n is an integer; 
 receiving a UL grant for a scheduled uplink (SUL) transmission to begin at the time unit n on the unlicensed band; 
 based on a priority class value for channel access for the SUL transmission being larger than a priority class value for channel access for the AUL transmission, terminating the AUL transmission, while the AUL transmission is ongoing and before the AUL transmission ends, such that a time gap remains after the AUL transmission and before the time unit n at which the SUL transmission is scheduled to start; and 
 performing the SUL transmission starting from the time unit n on the unlicensed band.